Evolutionary bioenergetics of sporulation

Area of Science:

• Microbiology
• Biochemistry
• Evolutionary Biology

Background:

• Complex traits require significant energy, but free energy for biosynthesis is often scarce.
• Bacteria evolved persistence strategies, like sporulation, for survival in unfavorable environments.
• Sporulation is an ancient bacterial program, initiated when cellular energy is nearly depleted.

Purpose of the Study:

• To quantify the energetic cost of bacterial sporulation in ATP.
• To resolve the paradox of energy-intensive sporulation occurring under energy-depleted conditions.
• To understand how metabolic constraints influence sporulation efficiency and evolution.

Main Methods:

• Integrated time-resolved genome, transcriptome, and proteome profiles.
• Quantified ATP cost of the full spore cycle (formation and revival).
• Incorporated energetic cost estimates into mechanistic models.

Main Results:

• Bacterial sporulation requires nearly 10^10 ATP, approximately 10% of the total cellular energy budget.
• The majority of sporulation's energy cost is attributed to translation, membrane synthesis, and protein turnover.
• Sporulation is optimal for long-term survival (months or longer) due to its trade-off between immediate cost and delayed benefit.

Conclusions:

• Sporulation is one of the most energy-intensive processes in bacterial cells.
• Metabolic constraints significantly shape sporulation efficiency.
• Even modest energetic burdens during sporulation can influence bacterial evolution and trait maintenance.